The invention relates to electric brush motors and more particularly, to brush holders for hammer-type brushes.
In conventional electric brush motors provided with a hammer brush holder, an end of the carbon brush is inserted into a boxed-shaped receptacle of the hammer brush holder. The receptacle is configured and dimensioned to hold the carbon brush through a clamping action. However, with this structure, an inadequate clamping effect can occur when the applicable end of the carbon brush is introduced into the receptacle. Typical brush holders also do not adequately thermally and electrically isolate the brush or suppress electromagnetic radiation.
Accordingly, there is a need for an improved brush holder for a hammer brush that mechanically clamps the brush, thermally and acoustically isolates the brush, applies a current path to the brush, and suppresses electromagnetic radiation.
An object of the present invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is obtained by a providing a brush holder for holding a hammer brush of an electric motor. The brush holder includes a single piece of wire bent to define a brush-engaging portion having an opening, and a torsion spring structure connected to and spaced from the brush-engaging portion. The brush-engaging portion is constructed and arranged to prevent rotation of the hammer brush when disposed in the opening.
In accordance with another aspect of the invention, a method is provided for holding a hammer brush of an electric motor. The method provides a brush holder comprising a single piece of wire bent to define a brush-engaging portion defining an opening, and a torsion spring structure connected to and spaced from the brush engaging portion. The brush-engaging portion is constructed and arranged to prevent rotation of the hammer brush when associated therewith. A generally cylindrical member is provided for locating the brush. The torsion spring structure is placed over the cylindrical member and the hammer brush, having non-machined sides, is inserted into the opening so that the brush-engaging portion contacts the sides of the brush.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.